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Privacy Policy

Last updated: 2026-07-29

Styx Multi-Cart (“the extension”) runs between your browser and Amazon. There is no Styx server, and no account to create with us. This page explains, in plain language, what data the extension touches and where it goes.

Where your carts actually live

Your carts are your own Amazon lists, stored in your Amazon account — not in the extension, and not on any server of ours.

When you save a cart, the extension creates or updates a list in your Amazon account, acting on your behalf through your existing Amazon session. That is also why your carts appear on every device you sign in to: Amazon is holding them, not us. It also means uninstalling the extension does not delete your carts — they remain in your Amazon account until you delete them there.

Using the extension therefore requires being signed in to Amazon.

Data the extension stores locally

The extension stores only a small set of settings and state in your browser via the chrome.storage.local API:

Earlier versions of the extension stored full cart snapshots locally. That model has been replaced by Amazon lists; any snapshots left over from an older version stay on your device and are erased when you uninstall or clear extension storage.

Data we never collect

Network requests the extension makes

There are two categories of outbound requests:

1. Requests to Amazon

When you empty your cart, save a cart, send a cart to your Amazon cart, or add an item while browsing, the extension drives Amazon pages on your behalf — reading your cart and lists, opening product pages, clicking “Add to Cart,” and deleting cart rows. These requests go directly from your browser to Amazon, using your existing Amazon session, exactly as if you had clicked the buttons yourself. Some of these actions write to your Amazon account: creating a list, adding items to it, and removing items from your cart.

About the tag= parameter in add-to-cart links. If you inspect the URLs the extension opens when sending a whole cart to your Amazon cart, you’ll see an Amazon Associates–style parameter (tag=styxmcart-20). Amazon’s bulk add-to-cart endpoint refuses to render the items without one, so the extension supplies a placeholder to make the feature work. It is not a registered Associates account, and we earn no commission or referral fee from your purchases. The parameter carries no information about you and does not track your browsing.

2. Requests to the payment / license provider (Premium only)

If you purchase a Premium subscription, the extension uses ExtensionPay (which uses Stripe for payment processing). In that context:

Users who never click the Upgrade button are never contacted by ExtensionPay or Stripe, and no payment-related data is generated — the SDK short-circuits to a local “not paid” response without making any network request.

Users who click Upgrade (whether or not they complete the purchase) have a randomly generated ExtensionPay API key written into their local chrome.storage.local, and the daily license-status check begins from that point. The check transmits only the opaque API key and never reveals which Amazon storefronts you use, which carts you’ve saved, or any other behavioral data from this extension.

Permissions

The extension requests the following Chrome permissions, each used solely for the purpose described:

A more detailed per-permission justification is on the permissions page.

Children

The extension is not directed to children under 13 and does not knowingly collect any data from anyone.

Changes to this policy

If the extension’s data handling changes in the future, this page will be updated and the “Last updated” date at the top will be revised. Material changes will also be noted in the extension’s release notes on the GitHub repository.

Contact

Questions, complaints, or takedown requests: